Line currents in electric power distribution cables are commonly used to produce auxiliary power. This auxiliary power often referred to as “scavenged power,” is used to power a variety of devices used in monitoring and controlling electrical distribution.
One major limitation of scavenging power from line currents is the elimination of that power source when a downstream fault occurs. In the case of a recloser, for example, a fault may result in the opening of the line at that point, which in turn eliminates the flow of the current upstream of the trip. In such a situation, any device relying on current flow for power will not function. If, for example, a recloser relied on such a power source, it may not have the power to maneuver the reclosing mechanism and close or open the breaker. For this very reason, reclosers include internal batteries to power the device when the line is open.
Many other power system applications, and specifically power distribution systems, require a battery to supply power when line current is eliminated. Examples of these applications include fault indicators, wireless transmitters, IEDs, reclosers etc. However, batteries are relatively expensive and have a limited practical life.
There is therefore a need in the art for a power system that continues to power electrical devices even when the line current is eliminated.